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High levels of dietary homocysteine (Hcy) accelerate impulse propagation across the murine atrioventricular node (AVN)
Author(s) -
Maldonado Claudio,
Moshal Karni,
Todnem Nathaniel D,
Soni Chirag V,
Pushpakumar Sathnur B,
Tyagi Suresh C
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.58
Subject(s) - medicine , cardiology , intracardiac injection , homocysteine , endocrinology
Patients with elevated levels of Hcy have been reported to be at greater risk of developing cardiac arrhythmias and sudden cardiac death (SCD). However, the mechanism that initiates Hcy‐induced arrhythmias is unknown. Since intracellular Ca 2+ is important in the modulation of AVN conduction and Hcy regulates Ca 2+ transients, we hypothesize that Hcy increases impulse conduction across the AVN facilitating conduction of atrial tachyarrhythmias to the ventricles. Using intracardiac electrophysiologic techniques, we report that in diet induced hyperhomocysteinemic (HHcy) C57BL/6 mice, high levels of Hcy elicited significantly shorter PR intervals (P=.0056) than in mice on a regular diet. The AH interval of intracardiac electrograms in HHcy mice revealed an accelerated conduction (32.4±6.0msec) compared to controls (44.0±7.3msec, P=.0069). However, HV conduction remained unchanged. Ventricular programmed stimulation demonstrated a trend to induced non‐sustained ventricular tachycardia (VT) in HHcy mice. Our preliminary results demonstrate for the first time that high levels of dietary Hcy increase impulse propagation from atria to ventricles suggesting a potential mechanism for conduction of supraventricular arrhythmias in HHcy mice.